Malaria is one of the oldest diseases to have affected our primate ancestors, even long before homo sapiens ever existed. Sadly, it is extremely deadly in humans, so scientists around the world are always searching for innovative ways to tackle the disease, such as vaccines or even genetically modifying mosquitoes.
The creatures that cause malaria
Six parasite species spread malaria amongst humans, one of these is named P.malarie. A team at the University of Edinburgh has managed to gain valuable insight into this microorganism and homed in on its origins.
In the 1920s, scientists took a close look under a microscope and identified that chimpanzees could be infected with a seemingly identical parasite to P.malarie. It was always thought to be the same species, but no genetic analysis was carried out, creating a century-long presumption about the sample.
Where did P.malarie come from?
This is where the Scottish scientists come in. Through cutting-edge genetic analysis techniques, the samples could finally be compared to confirm what species they contained. Although they looked similar, three distinct strains were identified. P.malarie, the human infecting species, and two others that only infect apes.
One of these parasites can be found in chimpanzees, bonobos, and gorillas across Central and West Africa, and is distantly related to P.malarie. The other ape parasite is much more closely related to the human-infecting species. Following this lead, further genetic analysis revealed this was likely P.malarie’s ancestor which managed to hop over from apes to humans.
Inspiring future parasite treatment
This study has helped explain the evolutionary link between malaria parasites that infect humans and their original ape-infecting ancestors. Although P. malariae brings about a mild form of malaria, it can still result in chronic, life-long infections. Understanding the evolutionary history of this strain is valuable for treatment and gauging human-parasite relationships generally.
“Among the six parasites that cause malaria in humans, P. malariae is one of the least well understood. Our findings could provide vital clues on how it became able to infect people, as well as helping scientists gauge if further jumps of ape parasites into humans are likely,” explained study author Dr. Lindsey Plenderleith.
Source study: Nature Communications – Zoonotic origin of the human malaria parasite Plasmodium malariae from African apes